Technical Field
The present disclosure relates to an internal combustion engine that includes a manifold channel that collects, into one, exhaust gases from a plurality of cylinders and a catalytic device that is arranged on the downstream side of this manifold channel.
Background Art
JP 10-037746 A discloses an exhaust pipe having a double-pipe structure in order to reduce the heat released from exhaust gas to the exhaust pipe. This exhaust pipe (more specifically, an exhaust manifold) is provided with an inner pipe through which the exhaust gas flows and an outer pipe that forms a hollow layer with the inner pipe. The inner pipe is formed by combining a pair of half bodies that are formed by press molding. The outer pipe is formed by combining a pair of half bodies that are formed by press molding in such a manner that the inner pipe is sandwiched in between this pair of half bodies. To be more specific, in a manner such that a flange portion of the pair of half bodies of the inner pipe is sandwiched in between a flange portion of the pair of half bodies of outer pipe, these flange portions are welded together.
JP 10-037746 A is a patent document which may be related to the present disclosure.